2013 Sustainability Report

As one of the largest owners and developers of office properties in the United States, we continually seek ways to promote our growth and improve our performance by attracting and retaining tenants and controlling our costs. The efficient operation of our buildings in an environmentally responsible manner and positively impacting the communities in which we operate are important components of this strategy.

Boston Properties reviews on an ongoing basis which measures are the most effective in supporting this strategy and where the greatest risk lies in not taking action. We focus our efforts on the areas we can control and make significant impacts. These include the design and construction of our new developments and the operation of our existing buildings. While our sustainability management and investments reach across our portfolio, we have focused this report on the aggregate performance of office buildings over which we have full control of the operational systems and information and which are at least fifty percent occupied.

Office buildings comprise the vast majority of our portfolio and by concentrating on similarly situated buildings we are able to compare performance and judge the effectiveness of our sustainability measures in a more meaningful way. Except as otherwise indicated, the energy efficiency and water conservation data presented in this report relates to these types of office buildings. Based on our assessment, we apply the effective measures in our other property types, as appropriate.

Over time we will continue to assess the available data and determine when to expand this report to address other property types and information. Boston Properties has followed the development of several other approaches for reporting on sustainability performance, including surveys which include all industries and more recent efforts to establish surveys focused on the real estate industry.

We are pleased to report that in 2012 we participated in the Global Real Estate Sustainability Benchmark (‘‘GRESB’’) report because it is tailored to the issues which are important to the real estate industry and its investors, and the sponsors of the report have committed to working with the industry to make the results of the report more meaningful. The success of the Boston Properties sustainability program is demonstrated by our ranking in the results of the GRESB report in the top fifth of all respondents and the top third of our peer group of office property owners in the United States. Boston Properties also participated in the NAREIT Leaders in the Light competition to recognize superior sustainability performance, which is now based on the GRESB report with the addition of topics of interest to the REIT industry.

We look forward to working with the sponsors GRESB and NAREIT to discuss our ideas so that their programs will provide useful information regarding our sustainability program in addition to this report. Our sustainability efforts are centered on energy efficiency, waste reduction, water conservation and maintaining a quality environment for our tenants through our green cleaning program. As a company with a core strategy of long-term ownership, we use high quality building materials and design to reduce replacement costs and repairs and to ensure our buildings remain competitive for the long term.

We invest in energy systems which reduce the cost of operations for ourselves and our tenants. A core element of our development strategy is a commitment to the U.S. Green Building Council’s LEED® (Leadership in Energy and Environmental Design) certification program. We also partner with our tenants to further their sustainability objectives, particularly with regard to large tenancies and build-to-suit projects. An example is the development of Weston Corporate Center described in the Case Studies later in this report.